The present invention relates to folding slat type chairs and more generally to X-shaped folding supports or cradles.
A number of folding X-configured chairs are available in the art. Conventionally, to my knowledge, the two legs of the X are attached to a screw or pivot pin for folding and unfolding and may include a stop mounted on one of the legs to establish the unfolded separation of the legs at a desired angle for sitting and to provide stability. Closely representative of such a design is U.S. Pat. No. 404,589 issued in the name of Batt, which discloses seat and back sections which are pivotally joined by a pin and a cross bar or stop which is joined to the bottom of the seat for defining the angle between the opened back and seat. U.S. Pat. No. 1,342,650 issued to Schlegel, also discloses a folding chair in which back and seat sections are commonly mounted on a pivot pin. In addition, a pair of cross bars or members are provided, one mounted to the rear of the back above the seat and the other mounted beneath the seat in front of the back (or leg) section, again apparently to define the angle between the opened back and seat.
To my knowledge, the screws or pins are used in prior art chairs to lock the seat and back sections together and to thus provide stability. The use of pivot pins however, fixes the position of the seat relative to the back and vice versa. Among other limitations, this prevents adjustment of the length of the seat or back during use and adjustment of the relative longitudinal position of the seat and back when folded.